A tape drive used in magnetic tape applications may be provided with one or more magnetic tape heads that each include one or more head elements, e.g., thin film magnetic transducers, for performing read and/or write operations on a magnetic tape. For each tape head, the one or more head elements are typically fabricated on a substrate and covered with a top closure. A thick overcoat layer of alumina is also typically deposited between the head elements and the top closure.
During operation of the tape drive, the tape may be biased against the face of the tape head or heads as the tape is moved longitudinally relative to the heads. Rubbing between the tape and the tape heads may cause both items to wear. The substrates and closures of the tape heads are fabricated from hard materials to help minimize their wear. The head elements and associated overcoat layers, on the other hand, are fabricated from materials selected primarily for their magnetic and electrical properties, and may be softer than the substrates and closures.
The difference in hardness between the substrate and closure materials, on the one hand, and the head element and overcoat layer materials, on the other hand, may result in uneven wear at the face of the tape head due to contact with the tape. Because the head element and overcoat layer materials may be softer than the substrate and closure materials, the head element and overcoat layers may recess more quickly from the tape-head interface than do the substrate and closure. As a result, a concave shaped gap may develop over time between the head elements and the tape. This gap may cause poor read and write performance, and even total failure of the tape heads in severe recession cases.
A prior attempt to reduce wear of a tape head involved coating the tape head with a first layer of non-conductive silicon nitride, and a second layer of titanium applied over the layer of silicon nitride. Titanium has good wear characteristics, but it is conductive. As a result, the non-conductive silicon nitride layer is provided as an isolation layer between the tape head and the titanium layer.